Writebol was outfitted in a hazmat suit as she was wheeled in on a stretcher by two medics in protective suits, CNN reports.

The two Americans contracted the deadly disease while working with infected patients in Liberia. They were flown to the U.S. for treatment.

"The quality of care here in the United States certainly far, far, far surpasses any that they're able to receive in those western African nations where they're having so much turmoil as well as so much illness and so few resources," Dr. Lee Norman, chief medical officer at The University of Kansas Hospital, tells PEOPLE.

Dr. Brantly is continuing to improve since arriving in the States on Saturday, according to his wife.

"I am thankful for the professionalism and kindness of Dr. Ribner and his team at Emory University Hospital," Amber Brantly, 30, said in a statement on Tuesday. "I know that Kent is receiving the very best medical treatment available."

She added: "I am also thrilled to see that Nancy arrived safely in Atlanta today. Our families are united in our faith in Jesus, and we will walk through this recovery time together. Please continue to pray for Kent, Nancy and the people of Liberia."

Meanwhile, at Mt. Sinai Hospital in New York, doctors are awaiting the test results of a man who recently returned from West Africa with Ebola-like symptoms. He was isolated at the hospital on Monday morning as a precaution, but health officials say it is "unlikely" that he has the virus.

For more about the Americans fighting Ebola, pick up this week's issue of PEOPLE.